WatiN框架学习二——对弹窗的处理

以IE为例，WatiN处理弹出窗口：

            IE ie = new IE("string"); //打开指定web页
            ie.Button(Find.ById("string")).Click(); //点击相应的按钮弹出需要测试的窗口TestSecondWindow
            IE newIE = IE.AttachTo<IE>(Find.ByTitle("TestSecondWindow")); // 查找新窗口TestSecondWindow并赋给新的IE对象
            //TODO: write the code you need to test in newIE  

WatiN处理confirm对话框：

         IE ie = new IE(string); //打开指定web页
         ConfirmDialogHandler cdh = new ConfirmDialogHandler();
         ie.AddDialogHandler(cdh); //将ConfirmDialogHandler对象与IE建立关联
         ie.Button(Find.ById(string)).ClickNoWait(); //记住这里要用ClickNoWait而不能用Click,否则在模式窗口关闭之前代码不会继续执行。
         cdh.WaitUntilExists();
         cdh.OKButton.Click(); 
         ie.WaitForComplete();
         ie.RemoveDialogHandler(cdh); // ConfirmDialogHandler对象与IE取消关联

这里需要注意的是Click()方法与ClickNoWait()方法的区别，先来看看Click()方法

        /// <summary>
        /// Clicks this element and waits till the event is completely finished (page is loaded 
        /// and ready) .
        /// </summary>
        public virtual void Click()
        {
            ClickImpl(true);
        }

接下来是ClickNoWait()方法：

        /// <summary>
        /// Clicks this instance and returns immediately. Use this method when you want to continue without waiting
        /// for the click event to be finished. Mostly used when a 
        /// HTMLDialog or javascript popup is displayed after clicking the element.
        /// </summary>
        public virtual void ClickNoWait()
        {
            ClickImpl(false);
        }

从上面两段代码上看，可以发现，它们都调用了ClickImpl(bool xxx)方法，只是一个是true一个是false，那么被定义的bool值又是什么呢？找到ClickImpl()方法：

        /// <summary>
        /// Handles the implementation of Click and ClickNoWait
        /// </summary>
        protected virtual void ClickImpl(bool waitforComplete)
        {
            if (!Enabled)
            {
                throw new ElementDisabledException(IdOrName, this);
            }

            Logger.LogAction((LogFunction log) => { log("Clicking (no wait) {0} '{1}', {2}", GetType().Name, IdOrName, Description); });

            Highlight(true);

            if (waitforComplete)
            {
                FireEvent("onclick");
            }
            else
            {
                FireEventNoWait("onclick");
            }

            try
            {
                if (waitforComplete) WaitForComplete();
            }
            finally
            {
                Highlight(false);
            }
        }

原来bool值表示的是WaitForComplete, 撇开其他代码，先找到下面判断语句：

            if (waitforComplete)
            {
                FireEvent("onclick");
            }
            else
            {
                FireEventNoWait("onclick");
            }

问题转变成FireEvent()方法及FireEventNoWait()方法之间的区别，先找到FireEvent()方法：

        /// <summary>
        /// Fires the specified <paramref name="eventName"/> on this element
        /// and waits for it to complete.
        /// </summary>
        /// <param name="eventName">Name of the event.</param>
        public virtual void FireEvent(string eventName)
        {
            FireEvent(eventName, true, null);
        }

看到这段代码，想来，和FireEventNoWait()方法之间的区别可能还会是其中某个bool值的区别，果不其然，看FireEventNoWait()方法：

        /// <summary>
        /// Only fires the specified <paramref name="eventName"/> on this element.
        /// </summary>
        public virtual void FireEventNoWait(string eventName)
        {
            FireEvent(eventName, false, null);
        }

这两个方法都是调用FireEvent(string xxx, bool xxx, ?)方法，且区别仅在于bool值的设定，先不管，跳到这个方法看看先：

        private void FireEvent(string eventName, bool waitForComplete, NameValueCollection eventProperties)
        {
            if (!Enabled)
            {
                throw new ElementDisabledException(IdOrName, this);
            }

            Highlight(true);

            if (waitForComplete)
            {
                NativeElement.FireEvent(eventName, eventProperties);
                WaitForComplete();
            }
            else
            {
                NativeElement.FireEventNoWait(eventName, eventProperties);
            }

            Highlight(false);
        }

到这里会发现，重点在以下代码中：

            if (waitForComplete)
            {
                NativeElement.FireEvent(eventName, eventProperties);
                WaitForComplete();
            }
            else
            {
                NativeElement.FireEventNoWait(eventName, eventProperties);
            }

而最主要的在于WaitForComplete()方法的调用上，也就是在ClickNoWait()方法边上注释上所说的，如果用Click()方法，代码在往下走之前一定会等待模式窗口关闭，一旦关闭才是WaitForComplete()完成，因此，使用Click()方法的话，表面看起来整个程序会停着不动，从而达不到对对话框的处理效果。